1) Passing through of further NMEA data: The data is passed through only in one way that means pc data do not go back through easyAIS into the GPS.2) Reduction of the baudrate: it is generally o.k. Many of our customers are using the lower baudrate of 4800 because of different facts. To do that we have had a jumper on the board in the first generation of easyAIS products. Now we do it by a special start up procedure which is described in the manual of the easyAIS 2nd generation. But it takes a little bit longer with 4800 baud until you have all data on your pc.
The typical result of the lower baudrate: For example if you have 160 targets (at the moment we know the Rotterdam harbour is the only one which has such a high number of targets) With 4800 Baud it takes about 40 seconds until you get all the dynamic data onto your display. If it is no problem for you to wait to receive the objects onto your display, you can use one port with 4,8 kB. But if you would like to have the objects in real-time you should prefer to use maybe a 2nd port where you can get the easyAIS NMEA data by 38400 Baud.